Filter
Top Products
MAINTENANCE AND REPAIR INSTRUCTIONS
18
Checking the fuel mixture, cleaning the air filter, and
adjusting the idle speed screw should solve most engine
problems.
If not and:
• The engine will not idle,
• The engine hesitates or stalls on acceleration,
• There is a loss of engine power,
have the carburetor adjusted by an authorized service
dealer.
Idle Speed Adjuster
Fig. 27
REPLACING THE SPARK PLUG
Use a Champion RDJ7Y spark plug (or equivalent). The
correct air gap is 0.020 in. (0.5 mm.). Remove the plug
after every 25 hours of operation to check its condition.
1. Stop the engine and allow it to cool. Grasp the plug
wire firmly and pull the cap from the spark plug.
2. Clean dirt from around the spark plug. Remove the
spark plug from the cylinder head by turning a 5/8 in.
socket counterclockwise.
Note: Replace cracked, fouled or dirty spark plug.
3. Set the air gap at 0.020 in. (0.5 mm.) using a feeler
gauge (Fig. 28).
0.020 in.
(0.5 mm.)
Fig. 28
CAUTION: Do not sand blast, scrape, or clean
electrodes. Grit in the engine could damage the
cylinder.
4. Install a correctly gaped spark plug in the cylinder
head. Tighten by turning the 5/8 in. socket clockwise
until snug.
If using a torque wrench torque to;
110-120 in.•lb.. (12.3-13.5 N•m).
Do not over tighten.
CARBURETOR SETTING
The idle speed adjuster of the engine is adjustable
though the Air filter/muffler cover (Fig 27).
NOTE: Careless adjustments can seriously damage your
unit. An authorized service dealer should make
carburetor adjustments.
Check Fuel Mixture
Old and/or improperly mixed fuel is usually the reason
for the unit not running properly. Drain and refill the tank
with fresh, properly mixed fuel prior to making any
adjustments. Refer to Oil and Fuel Information.
Clean Air Filter
The condition of the air filter is important to the
operation of the unit. A dirty air filter will restrict air flow
and change the air/fuel mixture. This is often mistaken
for an out of adjustment carburetor. Check the condition
of the air filter before adjusting the idle speed adjuster.
Refer to Air Filter Maintenance.
Adjust Idle Speed Adjuster
WARNING: This unit will need to be running
during idle speed adjustment. Wear
protective clothing and observe all safety
instructions to prevent serious personal injury.
Also, DO NOT set unit on any surface except a
clean, hard area while starting or performing any
adjustments. Debris such as gravel, sand, dust,
grass, etc. could be picked up by the air intake
and thrown out by the discharge opening,
damaging unit, property, or causing serious
injury to bystanders or operator.
If after checking the fuel mixture and cleaning the air
filter the engine still will not idle, adjust the idle speed
adjuster as follows.
1. Start the engine and let it run at a high idle for a
minute to warm up.
2. Set the blower/vacuum mode change-over lever to
the up position (Blower Mode). See Operating as a
Blower.
NOTE: Setting the lever to the blower mode prevents
the vacuum bag from filling up while starting or
running the unit.
3. Move the throttle control and let the engine idle. If
the engine stops, insert a small phillips or flat blade
screwdriver into the hole in the air filter/muffler cover
(Fig. 27). Turn the idle speed adjuster in, clockwise,
1/8 of a turn at a time (as needed) until the engine
idles smoothly.
4. If the unit appears to be idling too fast, turn the idle
speed adjuster counterclockwise 1/8 of a turn at a
time (as needed), to reduce idle speed.